<script>
  var str = '123*abc.456';
  console.log(str.search('.*'));        // 输出结果：0
  console.log(str.search(/[\.\*]/));    // 输出结果：3
</script>

<script>
  var str = 'test@123.com';
  var reg = /[@\.]/;
  var split_res = str.split(reg);
  console.log(split_res);    // 输出结果：(3) ["test", "123", "com"]
</script>

<script>
  var str = 'We are a family';
  var reg = /\s/;
  var split_res = str.split(reg, 2);
  console.log(split_res);    // 输出结果：(2) ["We", "are"]
</script>